Receptacle for sorting and handling flat articles such as letters

ABSTRACT

A receptacle which can be employed as a tray for collecting groups of thin generally flat articles, typically letters, during sorting and which can be combined with an identical but inverted receptacle to provide a complete container in which the collected group of articles can be transported. Constructed to be advanced by a conveyor beneath a series of article retaining stations, with the articles dropped one by one into the receptacle, the receptacle has an upwardly and rearwardly inclined trailing end wall, to support the first article dropped into the receptacle, and a series of upwardly opening transverse notches respectively arranged to receive the lower edges of the first and subsequent other articles dropped into the receptacle, the configuration and disposition of the notches being such that the dropped articles collect in the receptacle as an orderly group with all of the articles oriented in the same fashion, e.g., addresses of envelopes all facing the same way.

Unite States Henig a'i tent 1 RECEP'IACLE FOR SORTING AND HANDLING FLATARTICLES SUCH AS LETTERS [75] Inventor: Seymour Henig, Kensington, Md.

[73] Assignee: John 1. Thom & Company,

Rockville, Md.

[22] Filed: May 12, 1971 [21] App]. No.: 142,599

[ Aug. 28, 1973 1,401,306 4/1965 France 220/97 F 216,917 1/1942Switzerland 206/72 Primary Examiner-Leonard Summer I vAttorney-Roylance, Abrams, Berdo and Kaul ABSTRACT A receptacle whichcan be employed as a tray for collecting groups of thin generally flatarticles, typically letters, during sorting and which can be combinedwith an identical but inverted receptacle to provide a completecontainer in which the collected group of articles can be r 1: ported.Constructed to be advanced by a conveyor beneath a series of articleretaining stations, with the articles dropped one by one into thereceptacle, the receptacle has an upwardly and rearwardly inclinedtrailing end wall, to support the first article dropped into thereceptacle, and a series of upwardly opening transverse notchesrespectively arranged to receive the lower edges of the first andsubsequent other articles dropped into the receptacle, the configurationand disposition of the notches being such that the dropped articlescollect in the receptacle as an orderly group with all of the articlesoriented in the same fashion, e.g., addresses of envelopes all facingthe same way.

9 Claims, 15 Drawing Figures Patented Aug. 28, 1973 3,754,646

3 Sheets-Sheet l j I INVENTOR 2O l9 SEYMOUR HEN/G Patent ed Aug. 28,1973 3,754,646

3 Sheets-Sheet 2 INVENTOR SEYMOUR HENIG "I. I. 'l 1 I l 1"!) V/l/I 1]Patented Aug. 28, 1973 3 Sheets-Sheet 3 INVENTOR SEYMOUR HEN/GRECEPTACLE FOR SORTING AND HANDLING FLAT ARTICLES SUCH AS LETTERSBACKGROUND OF THE INVENTION It is frequently necessary to sort flatarticles into groups of like articles and to handle and transport theresulting groups of articles. Thus, as described in my U. S. Pat. No.3,300,066, issued Jan. 24, I967, letters can be sorted automatically bydelivering each letter into one of a horizontally extending series ofupright storage slots, and dropping the letters selectively onto aconveyor arranged beneath the storage slots, the operation being suchthat letters of like characteristic, e.g., addresses are deposited inoverlapping relation to form a group supported by the conveyor.

Sorting procedures of this general type are highly advantageous butinvolve a number of subsidiary problems. Thus, it is difficult toachieve the desired neatness and preciseness of grouping by simplydropping the letters or other articles edgewise onto a flat support suchas a conveyor belt. Further, groups of letters so produced retain theirintegrity as a group only because of the support afforded by, e.g., theconveyor belt, and handling and transport of the groups requires thatthey be secured in some fashion, as by a band or by tying with string.And, so long as the groups have not been secured in some fashion, theycannot easily be manipulated, e.g., diverted for later addition of morearticles.

Attempts to solve such problems in the prior art have not been trulysatisfactory, particularly in the context of highly automated articlesorting and handling. Though the groups can be secured adequately, as bybanding, for transport, securing them in that fashion is allowable onlyafter all sorting operations are complete, and it has thus been thoughtto be necessary to accumulate the articles in loose groups and retainthe groups in that form until sorting has been completed. The usualportable receptacles employed in sorting of articles such as letters(e.g., mail bags, relatively large baskets, etc.) offer little if anyadvantage in automated systems. Accordingly, there has been a continuingneed for some portable handling means capable of at least retaining thegroups in proper form during sorting and handling.

OBJECTS OF THE INVENTION A general object of the invention is to devisea receptacle which serves both to orient flat articles in apredetermined fashion as they are dropped therein and thereafter tomaintain the articles in their oriented relation.

Another object is to provide such a receptacle which is hermaphroditicin the sense that two identical receptacles can be combined to form aclosed container which will preserve the oriented relation of a group ofarticles, one of the receptacles forming the bottom of the container andthe other the top.

A further object is to provide a receptacle capable of being used toreceive, arrange and retain letters or like flat articles droppedindividually in succession from a series of retaining stations as thereceptacle is advanced along a path below the series.

SUMMARY OF THE INVENTION Receptacles according to the invention comprisea bottom wall which is wider than the maximum length of the flatarticles to be handled and has a length which is great in comparison tothe thickness of the articles. At one end (the trailing end when thereceptacle is moved beneath a series of article receptacles), thereceptacle has an inclined end wall which slants upwardly and away fromthe bottom wall. The upper surface of the bottom wall presents aplurality of upwardly opening notches extending transversely of thereceptacle and arranged in a side-by-side series progressing lengthwiseof the receptacle, the effective width of the notches being larger thanthe thickness of the lower edges of the articles to be collected in thereceptacle. The series of notches includes a first notch extendinggenerally along the lower edge of the inclined end wall. When used forsorting letters, the receptacle is advanced along a path below a seriesof letter receptacles and a first letter is dropped into the receptaclewhen the first notch is located to receive the same. The relationshipbetween the first notch and the inclined end wall is such that, when thefirst letter has been dropped, continued advance of the receptaclecauses that letter to pivot rearwardly, coming to rest on the inclinedend wall while the lower edge of the letter remains engaged in thenotch. A second letter can be dropped in the next notch, will likewisepivot rearwardly, and will come to rest on the first letter. Theprocedure can be continued until the receptacle is full, or until thedesired group of letters has been accumulated. Gravitational coactionof. the letters with the notched bottom wall and the inclined end wallcauses the letters to remain in a letter facing retained group, i.e., agroup in which the letters are in address facc-to-rear face contact withall address faces facing in the same direction, even though thereceptacle is moved, stored, and again moved, so long as the receptacleremains in upright position.

In advantageous embodiments, the receptacle has upright side and frontend walls and is so constructed that two of the receptacles can bejoined to form a closed container with the group of letters or otherarticles housed therein for transport.

In order that the manner in which the foregoing and other objects areachieved according to the invention can be understood in detail,advantageous embodiments thereof will be described with reference to theaccompanying drawings, which form a part of the original disclosure ofthis application, and wherein:

FIG. 1 is a'perspective view of a receptacle according to oneembodiment;

' FIGS. 2 and 2A are semidiagrammatic views in which the receptacle ofFIG. 1- is shown in longitudinal vertical cross section at twosuccessive letter-receiving stations;

FIGS. 3 and 4 are fragmentary transverse sectional views, enlargedrelative to FIG. 1, taken respectively on lines 3-3 and 4-4, FIG. I, andshowing themanner in which a second receptacle is applied as a cover tothe receptacle of FIG. 1;

FIG. 5 is a fragmentary longitudinal sectional view taken at thejuncture of the bottom and trailing end walls of the receptacle of FIG.1;

FIG. 5A is a view similar to FIG. 5 but showing a modified form of thereceptacle,

FIG. 6 is a perspective view of a closed container formed by two of thereceptacles of FIG. 1;

FIG. 7 is a front elevational view of a plurality of the containers ofFIG. 1 assembled in a nested stack and releasably retained by asupporting rack;

FIG. 8 is a perspective view of a receptacle according to anotherembodiment of the invention and also illustrates a hand tool usefultherewith;

FIG. 9 is a fragmentary perspective view showing the receptacle of FIG.8 in modified form;

FIG. 10 is a longitudinal sectional view of a closed container formed bytwo receptacles according to a further embodiment of the invention;

FIG. 11 is a longitudinal sectional view of a receptacle according toyet another embodiment;

FIG. 12 is a fragmentary longitudinal sectional view of a still furthermodified form of the receptacle of FIG. 8; and

FIG. 13 is a fragmentary top plan view of the receptacle of FIG. 12,showing the front end wall in closed position.

THE EMBODIMENT OF FIGS. l-7

In the embodiment of FIGS. l-7, the receptacle 1 comprises a bottom wall2, an upwardly and rearwardly inclined trailing end wall 3, and uprightfront end wall 4, and upright side walls and 6. The receptacle isadvantageously molded as an integral piece from a suitable polymericmaterial. Bottom wall 2 is of transversely corrugated configuration,presenting a plurality of straight, elongated, upwardly opening notches7 which extend transversely of the receptacle so as to be parallel toend walls 3 and 4. As best seen in FIG. 5, each notch 7 is of triangularcross section, being de fined by a flat rear surface 8 and a flat frontsurface 9. Bottom wall 2 is continuous, notches 7 extending from sidewall 5 to side wall 6.

Notches 7 can be considered as arranged side-by-side in a series whichprogresses from end wall 3 to end wall 4, with the first notch 7' of theseries extending along the bottom edge of the trailing end wall 3 insuch fashion that the front face of end wall 3 constitutes an extensionof surface 8 of notch 7.

Rear end wall 3 has a slant height which approximates three-quarters ofthe maximum width of the letters or other fiat articles to be collectedin the receptacle. Front end wall 4 extends upwardly at right angles tothe plane of bottom wall 2 for a distance approximately one-third theprojected height of wall 3 and terminates in a straight upper edge. Sidewall 5 includes flat lower portion 10 and a flat upper portion 11, thetwo portions 10, ll lying in vertical planes with the plane of portion11 displaced outwardly from that of portion 10 and the two portionsbeing integrally joined in such fashion that the lower edge of portion11 is defined by a downwardly facing outer shoulder 12. Similarly, sidewall 6 includes lower portion 13, upper portion 14, and a downwardlyfacing shoulder 15 along the lower edge of portion 14. The transversedimensions of the receptacle are such that the space between theopposing faces of portions II and I4 is very slightly greater than thedistance between the outer face of portion 10 and the outer face ofportion 13. At the front end of the receptacle, the front edges l6, 17of upper portions 11 and 14, respectively, slant upwardly and rearwardlyat the same angle of inclination as rear end wall 3, edges l6, 17 beingstraight and commencing at the upper edge of front wall 4.

The upper edges of side wall portions ll and 14 are straight andparallel to the bottom wall. The upper edge of portion 11 includes afront half 18, FIGS. 1 and 4, in the form of a straight elongated beadof circular transverse cross section such that the edge portion 18presents a right cylindrical surface extending for substantially morethan that surface joining inclined shoulders 19, FIG. 4. The upper edgeof portion 11 also includes a rear half 20 in the nature of a groovehaving a curved transverse cross section which extends for more than 180and has a radius of curvature substantially equal to that of the beadconstituted by upper edge portion 18. The upper edge of upper portion 14of side wall 6 is identical with that of portion 1 l of side wall 5 andincludes a front half in the form of a bead 21 and a rear half in theform of a groove 22.

The receptacle of FIGS. l-8 is particularly useful for collecting groupsof letters during sorting of mail in accordance with my U. S. Pat. No.3,300,066, and the manner of such use is illustrated in FIGS. 2 and 2A.The receptacle 1 is placed on the upper run of an endless horizontalconveyor belt 25 arranged to advance the receptacle along a horizontalpath below a horizontally extending series of letter-retaining stations26. Each station 26 defines an upright slot closed at the bottom by apivoted door 27. Letters previously identified as to category, e.g.,address, are delivered individually to the retaining station in themanner described in my patent No. 3,300,066 and can be releasedselectively by opening of the respective door 27. Receptacle l isadvanced by conveyor belt 25 until the first notch 7' is in apredetermined position below the first station 26 containing a letter ofthe category to be collected. Door 27 of that station is opened and theletter L drops by gravity toward receptacle 1, opening of the door 27being timed, relative to the speed of advance of receptacle 1 and thetime required for the letter to traverse the space between the station26 and receptacle 1, so that the notch 7 is located directly below thestation 26 when the lower edge of letter L reaches the bottom ofreceptacle 1. Accordingly, the lower edge of the letter enters notch 7and is guided into the bottom of that notch by the respective surfaces 8and 9. With receptacle 1 continuing to advance, and with the lower edgeof letter L now retained by notch 7', the letter pivots rearwardly,coming to rest on the front face of the inclined trailing end wall 3.When receptacle 1 advances to the proper position below the next station26 containing a letter L of the category to be collected, door 26 ofthat station is opened and letter L drops, with its lower edge enteringthe notch 7 immediately adjacent the preceding letter resting in notch7'. With receptacle 1 still continuing to advance, letter L' pivotsrearwardly (relative to the receptacle) to come to rest on letter L.This procedure continues either until an adequate number of letters iscollected during one pass beneath the series of stations 26, or untilthe receptacle has passed all of the stations 26 and, having collectedless than a predetermined number of letters, is diverted to storage forsubsequent recycle to receive additional letters.

As will be apparent from FIGS. l-2A, letters collected in the receptacle1 are arranged automatically in consistent orientation so as to beremovable as a group or stack ready for banding or tying. With theletters delivered intostations 26 with the addressed surfaces facing tothe right, as viewed in FIGS. 2 and 2A, all of the letters collected inreceptacle 1 will have their addressed surfaces facing in the samedirection, and the group of letters, when removed and tied, willaccordingly be ready for further handling, manually or by automatedequipment, in usual fashion.

When the collected group of letters is to be transported for asubstantial distance, as from city to city, the receptacle 1 in whichthe letters have been collected can be combined with another identicalreceptacle to form the closed container C, FIG. 6, in which the group ofletters is completely closed and retained in the same relation in whichthey were collected. Considering FIGS. 1-2A, it will be noted that theheight of side wall portions 11, 14 above the upper edge of front endwall 4 is equal to the projected height of that portion of wall 3 whichextends above the upper edges of portions ll, 14. Accordingly, a secondreceptacle 1, containing no letters, can be inverted and applied as acover to the first receptacle, with the beads 18, 21 being snapped intothe grooves 20, 22, respectively, to lock the two receptacles together.In the container C thus assembled, the end wall 3 of each receptacle 1extends over the edges 16, 17 of the other receptacle 1 and has its freeedge engaged with the upper edge of end wall 4 of the other receptacle.In this connection, the rear surface of trailing end wall 3 can bechamfered, as at 31, at the free edge in such fashion as to provide asurface which lies in the same plane as the front face of wall 4 of theother receptacle, in the assembled container C.

Since the combined heights of trailing end wall 3 and front end wall 4determine the interior space between the bottom walls 2 of the tworeceptacles making up the closed container C, FIG. 6, and since theslant height of wall 3 plus the effective slant height afforded by wall4 is approximately equal to the maximum width of the letters or otherarticles to be collected, the articles contained within container C areon the one hand prevented from pivoting excessively and on the otherhand retained and enclosed without being bent or deformed.

The distance between end walls 3 and 4,and the number of notches 7, areso selected that the receptacle can accommodate a predetermined numberof letters and, in normal mail sorting use, thatnumber will be collectedbefore the receptacle is transported to another location. Accordinglywhen the container C is assembled with such a group of letters in place,the integrity of the group is maintained even though, during transport,the container may be, e.g.,-completely inverted.

Since the distance between the outer faces of lower side wall portionsand 13 is slightly less than the distance between the inner faces of theupper side wall portions 11 and 14, a plurality of the receptacles 1 canbe arranged as a nested stack in the manner seen in FIG. 7. With thereceptacles thus arranged, retaining dogs 30 of stack support 31 can beengaged respectively beneath shoulders 12 and 15 of the lowermostreceptacle 1 to support the stack of receptacles. A second set ofretaining dogs 32 is provided which can be brought into and out ofengagement beneath the shoulders 12 and 15, respectively, of the nexthigher receptacle 1 in the stack. Accordingly, with dogs 32 engaged,dogs 30 can be actuated to release the lowermost receptacle, and thedogs 32 can then be disengaged to allow the stack to descend until thedogs 30, having been returned to their original positions, engage andsupport the newly arrived receptacle 1.

The effective mouth width of notches 7 is made large enough so that eachnotch 7 can accommodate an article of the maximum thickness contemplatedfor the articles to be collected in the receptacle. The effective mouthwidth of the notches should approximate the maximum thickness of thearticles to be handled and, advantageously, is made slightly greaterthan that thickness. Typically, when the receptacle is intended forhandling letters, the mouth width of notches 7 is on the order offive-sixteenth inch, taking one-fourth inch as the maximum thickness ofthe letters. The angle between surfaces 8 and 9 of the notches should beless than 90 and, advantageously, is. -85, with angle a being largerthan angle b. The included acute angle 0 between trailing end wall 3 andthe horizontal is, advantageously, in the range of 4,5-70.

ALTERNATIVE EMBODIMENTS In the embodiment of FIG. 8, the receptacle 51is generally like that of FIGS. 1-7, save that the bottom wall 52thereof is provided with two identical rows of notches 57 and 57, thenotches of the two rows being mutually aligned transversely of thereceptacle and the two rows of notches extending longitudinally of thereceptacle and being parallel'to each other. The two rows of notches arespaced apart and each row is spaced inwardly from the adjacent side wallof the receptacle. Bottom wall 52 includes a flat portion 52a, locatedbetween the row of notches 57 and side wall 55, a flat portion 5212,located between the two rows of notches, and a flat portion 520, locatedbetween the row of notches 57' and side wall 56.

Each transversely aligned pair of notches 57, 57' is operative toreceive and retain a fiat article to be collected, such as one of theletters illustrated in FIG. 8, in the same manner described withreference to notches 7 in the embodiment of FIGS. l-7.

A hand fork 40, with three flat parallel fingers 41 spaced apart so asto be respectively alignable with the flat portions 52a, 52b and 520,can be used to remove the collected letters as a group from thereceptacle.

As seen in FIG. 9, the receptacle of FIG. 8 can be modified by providingthe front wall 54 with upwardly opening rectangular notches 54a, 54b and540, so that the fingers of a hand tool or an automated unloader can beinserted longitudinally into the receptacle with the fingers eachentering via a different one of the notches 54a-54c. This modified formof receptacle has the advantage that the fingers of the unloading devicecan simply slide along the upper surfaces of flat bottom wall portions52a-52c without first being inclined to pass over the front wall of thereceptacle, as is the case with the embodiment of FIG. 8.

In both the receptacle of FIG. 8 and that of FIG. 9, the wall portionsdefining notches 57, 57' can be displaced upwardly out of the commonplane of flat portions 52a-52c in such fashion that the effective bottomof each notch is slightly above the upper surface of flat portionsSki-52c, providing free space between the bottom edges of the collectedletters and the flat portions of the bottom wall to accommodate thefingers of the unloading tool.

FIG. 10 shows an embodiment employing receptacles identical withreceptacle 51, FIG. 8, save that front wall 54 is eliminated entirely,inclined front side wall edges 62 and 67 are extended to the bottom ofthe receptacle, and rear wall 53 is extended so that when two of thereceptacles are fitted together to form a closed container, the rearwall 53 of each will close the front of the other. The embodiment ofFIG. 10, like that of FIG. 9, has the advantage that the fingers of theunloading tool can be inserted freely without interference by a frontwall, and has the additional advantage that a complete container formedfrom two of the receptacles is fully closed despite the absence of afront wall in each receptacle.

While the receptacle is advantageously provided with notches 7, 57 ofangular transverse cross section, it will be understood that the notchescan be of other configurations capable of receiving and retaining anedge of a flat article such as a letter. Thus, as illustrated in FIG.11, the receptacle of FIGS. 1-7 can be constructed with bottom wall 2a,trailing end wall 3a and front end wall 4a formed of a single piece ofsingle face corrugated box board, with the corrugations upwardly exposedas shown, the corrugations then defining the notches 7a.

In the embodiment of FIGS. 8 and 9, the front end wall 54 is fixed inupright position, its end and bottom edges being integral with therespective side and bottom walls of the receptacle. In the embodiment ofFIG. 10, the front wall of the receptacle is eliminated. FIGS. 12 and 13show an alternative embodiment in which the side, bottom and end wallsare formed as an integral structure from a suitable polymeric material,the front wall 154 being connected to bottom wall 152 by an integralflexible hinge comprising a narrow markedly thinned area 154! extendingtransversely of the receptacle completely along the juncture between thebottom wall and front wall. The material of thinned area 154' liesadjacent the bottom face of the bottom wall so that, when the front wall154 is pivoted to lie generally in the same plane as the bottom wall,the bottom face of the bottom wall and the corresponding face of thefront wall lie in a common plane, as seen in FIG. 12. Upwardlyandoutwardly diverging curved surfaces 160, 161, FIG. 12, extend betweenthe edges of the thinned area 154' and the upper face of the bottom walland the corresponding face of the front end wall, respectively. The sideedges of front end wall 154 are of generally triangular configuration,as indicated at 162, FIG. 13, and these edges snap resiliently into andout of engagement with mating grooves 163 which are of triangulartransverse cross section so that, as seen in FIG. 13, front end wall 154can be retained positively in its upright positon.

In all embodiments, the notches provided in the bottom wall can be of atransverse cross section other than triangular. Thus, as shown in FIG.A, surfaces 8' of the notches can be flat and angularly disposed as hereinbefore described, and surfaces 9' can advantageously be concave, asviewed from the opposite side of the notch, so that the lower edges ofthe letters or like articles deposited in the notches are positivelyretained against surface 9' even though the angle of repose of thearticle, established by trailing end wall 3', is acute.

What is claimed is:

l. A receptacle for use in collecting relatively thin, flat articlessuch as letters comprising, in combination a bottom wall having a widthgreater than the length of the articles to be collected and a lengthwhich is large in comparison with the average thickness of sucharticles;

an inclined first transverse end wall extending upwardly from one end ofsaid bottom wall,

said first end wall slanting upwardly and away from said bottom wall;the upper surface of said bottom wall presenting a plurality ofsubstantially identical upwardly opening notches which are effectivelyelongated transversely of said bottom wall and arranged in a serieswhich commences at the bottom of said first end wall and progresseslengthwise of said bottom wall toward the other end of said bottom wall,said notches being in parallel side-by-side relation and having a widthwhich is larger than the thickness of the lower edges of the articles tobe collected, the series of said notches including a first notch sodisposed that the bottom thereof extends generally along a line includedin the plane of said first end wall whereby, when the receptacle isadvanced lengthwise with said end wall at the trailing end of thereceptacle, a flat thin article dropped in such fashion that its loweredge enters said first notch will pivot rearwardly, with forwardmovement of the receptacle, and come to rest on said first end wall, anda flat thin article similarly dropped into the next notch of the serieswill likewise pivot rearwardly to come to rest on the article droppedinto said first notch; two side walls extending lengthwise of thereceptacle and each joined to a different end of said first end wall andto said bottomwall, the height of said side walls being less than thatof said first end wall; wherein the upper edge of each of said sidewalls is provided with first and second different latch means, saidfirst latch means being of such configuration and size as to coact witha latch means of the configuration and size of said second latch means,whereby a second identical receptacle, when inverted and disposed oversaid receptacle in endwise reversed relation thereto, can be secured tosaid receptacle as a cover; and a second transverse end wall secured toand projecting upwardly from said bottom wall, the height of said sidewalls being greater than the height of said second end wall, said sidewalls having inclined edge portions, at the ends thereof opposite saidfirst end wall, which slant downwardly and toward said second end wall,the dimensions of said first end wall said side walls, I and said secondend wall being such that, when said second receptacle is secured inplace as a cover, said first end wall of said second receptacle will liein flush engagement with said inclined edge portions of the receptaclebeing covered. 2. A receptacle according to claim I, wherein said firstend wall presents a substantially flat continuous surface, and saidbottom wall is relatively thin and of generally hill-and-valleyconfiguration following the shape of said notches. 3. A receptacleaccording to claim 1, wherein said first end wall is integral with saidbottom wall and constitutes a continuation of the corresponding wall ofsaid first notch. 4. A receptacle according to claim 1, wherein the wallof each of said notches which slants upwardly and toward said first endwall is inclined at a greater angle from a plane at right angles to saidbottom wall than is the wall which slants upwardly and away from saidend wall.

5. A receptacle according to claim 1, wherein said second end wall ispivotally connected to the end means for releasably securing said secondend wall in said closed position.

6. A receptacle according to claim 1, wherein said end wall is sodisposed that the included acute angle defined by said first end walland the plane of said bottom wall is in the range of from about 45 toabout 70.

7. A receptacle according to claim 6, wherein the included acute angledefined by said first end wall and the plane of said bottom wall isequal to the angle of the inclined edge portions relative to the planeof said bot- 5 tom wall.

8. A receptacle according to claim 1, wherein the length of said notchesis short in a direction transversely of said bottom wall and saidnotches are arranged in two parallel series, the notches of one seriesbeing aligned respectively with the notches of the other series, andsaid two series are spaced apart transversely of said bottom wall.

9. A receptacle according to claim 8 wherein said second transverse endwall is provided with an opening communicating with the space betweensaid two series of notches.

* ci s'ii"

1. A receptacle for use in collecting relatively thin, flat articlessuch as letters comprising, in combination a bottom wall having a widthgreater than the length of the articles to be collected and a lengthwhich is large in comparison with the average thickness of sucharticles; an inclined first transverse end wall extending upwardly fromone end of said bottom wall, said first end wall slanting upwardly andaway from said bottom wall; the upper surface of said bottom wallpresenting a plurality of substantially identical upwardly openingnotches which are effectively elongated transversely of said bottom walland arranged in a series which commences at the bottom of said first endwall and progresses lengthwise of said bottom wall toward the other endof said bottom wall, said notches being in parallel side-by-siderelation and having a width which is larger than the thickness of thelower edges of the articles to be collected, the series of said notchesincluding a first notch so disposed that the bottom thereof extendsgenerally along a line included in the plane of said first end wallwhereby, when the receptacle is advanced lengthwise with said end wallat the trailing end of the receptacle, a flat thin article dropped insuch fashion that its lower edge enters said first notch will pivotrearwardly, with forward movement of the receptacle, and come to rest onsaid first end wall, and a flat thin article similarly dropped into thenext notch of the series will likewise pivot rearwardly to come to reston the article dropped into said first notch; two side walls extendinglengthwise of the receptacle and each joined to a different end of saidfirst end wall and to said bottomwall, the height of said side wallsbeing less than that of said first end wall; wherein the upper edge ofeach of said side walls is provided with first and second differentlatch means, said first latch means being of such configuration and sizeas to coact with a latch means of the configuration and size of saidsecond latch means, whereby a second identical receptacle, when invertedand disposed over said receptacle in endwise reversed relation thereto,can be secured to said receptacle as a cover; and a second transverseend wall secured to and pRojecting upwardly from said bottom wall, theheight of said side walls being greater than the height of said secondend wall, said side walls having inclined edge portions, at the endsthereof opposite said first end wall, which slant downwardly and towardsaid second end wall, the dimensions of said first end wall said sidewalls, and said second end wall being such that, when said secondreceptacle is secured in place as a cover, said first end wall of saidsecond receptacle will lie in flush engagement with said inclined edgeportions of the receptacle being covered.
 2. A receptacle according toclaim 1, wherein said first end wall presents a substantially flatcontinuous surface, and said bottom wall is relatively thin and ofgenerally hill-and-valley configuration following the shape of saidnotches.
 2. A receptacle according to claim 1,wherein said first endwalL presents a substantially flat continuous surface, and said bottomwall is relatively thin and of generallyhill-and-valley configurat1onfollowing the shapeof said notches. 3 A receptacle according to claim1,wwherein said first end wall is integral with said bottom wall andconstitutes a continuation of the corresponding wall of said firstnotch.
 3. A receptacle according to claim 1, wherein said first end wallis integral with said bottom wall and constitutes a continuation of thecorresponding wall of said first notch.
 4. A receptacle according toclaim 1, wherein the wall of each of said notches which slants upwardlyand toward said first end wall is inclined at a greater angle from aplane at right angles to said bottom wall than is the wall which slantsupwardly and away from said end wall.
 4. A receptacle according to claim1, wherein he wall of each of said notches hhich slants upwardly andtoward said first end wall is inclined at greater ange from a plant atright angles to said bottom wall than is the wall which slants upwrdlyand away from said end wall.
 5. A receptacle according to claim 1,wherein said second11nd wall is pivotally connectedto the end of saidbottom wall opposite said inclined first end wall and is movable from anopen position, in which said bottom and second end walls are generallycoplanar, and a closed position, in which said second end wall bridgesthe space between the corresponding ends of said side walls, thereceptacle further comprising means for relaasably securing said secondend wall in said closed position.
 5. A receptacle according to claim 1,wherein said second end wall is pivotally connected to the end of saidbottom wall opposite said inclined first end wall and is movable from anopen position, in which said bottom and second end walls are generallycoplanar, and a closed position, in which said second end wall bridgesthe space between the corresponding ends of said side walls, thereceptacle further comprising means for releasably securing said secondend wall in said closed position.
 6. A receptacle according to claim 1,wherein said end wall is so disposed that the included acute angledefined by said first end wall and the plane of said bottom wall is inthe range of from about 45* to about 70*.
 6. A receptacle according toclaim 1, wherein sid en wall is so disposed that the included acuteangle defined by said first end wall and the plane of said bottom wallis in the range of from about 45* to about 70*. 7.a rece1tacle accordingto claim 6, whein the includd acute angle defined by said firtt end walland the plane of said bottom walliis equal to the angle of the inclinededge portionsrelative to the plan of sid bottom wall.
 7. A receptacleaccording to claim 6, wherein the included acute angle defined by saidfirst end wall and the plane of said bottom wall is equal to the angleof the inclined edge portions relative to the plane of said bottom wall.8. A receptacle according to claim 1, wherein the length of said notchesis short in a direction transversely of said bottom wall and saidnotches are arranged in two parallel series, the notches of one seriesbeing aligned respectively with the notches of the other series, andsaid two series are spaced apart transversely of said bottom wall.
 8. Areceptale accoding to claim 1, wherein the length of said notches isshort in a direction transversely of said bottom wall and said notchesare arranged in two parallel series, the nothes of one series beingaligned respectively w1th the notches of the oth series, and said twoseries are spaced apart transversely of said bottom wall.
 9. Areceptacle according to claim 8 wherein said second transverse end wallis provided with an opening communicating with the space between saidtwo series of notches.
 9. A receptacle according to claim 8 wherein saidsecond transverse end wall is provided with an opening communicatingwith the space between said two series of notches. heigh of 2aid sidewalls being less than that of said first end wal1; wherein the upperedge of ea ch of said side walls is provided with first and seconddifferent latch means, said first latch means being of suchconfiguration and size as to coact with a latch means of theconfiguration and size of said second latch means, whereby a secondidentical receptacl1, when inverted and disposed over said receptacle inendwise reversed relationtthereto, cnn be secured to said receptacle asa cover; and a second transverse end wall secued to and projectingupwardly from said bottom wall, the height of sai side walls beinggreater than the heightof said second en wall said side walls havinginclined edge portions, at he ends thereof opposite said first end wall,which slant downwardly and toward said second end wall, the dimensionsof sid first end wall said side walls, and said second end wall beingsuch that, when said second receptacle is secured in place as a cover,said first end wall of said second receptacle will lie in flushengagement with said inclined edge portions of the receptacle beggcovered.